Liz Truss has resigned as prime minister after facing an open revolt from her MPs in a tumultous 24 hours.
The Tory party leader confirmed her departure in a statement delivered outside Number 10 on Thursday.
She is set to become the shortest serving prime minister in history after a period of economic turbulence.
Ms Truss said: “I recognise…given the situation I cannot deliver the mandate on which I was elected by the Conservative Party.”
A leadership election will be completed within the next week Ms Truss confirmed, after speaking to the leader of the 1922 Committee, Sir Graham Brady, in No 10.
Allies of former leader Boris Johnson pushed for him to make a comeback, despite being forced out earlier this year.
There is also an expectation former Chancellor Rishi Sunak could throw his hat in the ring once more.
Chancellor Jeremy Hunt was quick to rule himself out as he focuses on calming the financial markets.
Michael Gove, who was brought up in Aberdeen, will also sit out the contest.
Andrew Bowie, MP for West Aberdeenshire and Kincardine, backs Mr Sunak to become the next leader of the party.
The north-east MP, who was a vocal supporter of the former chancellor in summer’s leadership contest, said he is the “only one with the plan to move us forward”.
There is only one person that can unite this party, get the economy on a firm footing. Only one with the plan to move us forward. And that is the same person I believed in over the Summer. It has to be Rishi.
— Andrew Bowie MP (@AndrewBowie_MP) October 20, 2022
Ms Truss will remain as prime minister until a successor has been chosen.
Banff and Buchan MP David Duguid, who backed Ms Truss earlier this week, said he respects her decision and the “dignity with which she has acted”.
He added: “What this country needs now, above all else, is a stable base from which we can continue delivering both the recovery from Covid and protection from global turmoil, all while striving for essential economic growth.”
Aberdeen South SNP MP Stephen Flynn said the outgoing Tory leader has “managed to eclipse Boris Johnson as the worst prime minister in living memory”.
He added: “The Tories cannot be left to try and clear up the chaos they have created – a general election must happen and the people of Scotland given the opportunity to chose an independent future.”
First Minister Nicola Sturgeon, Labour leader Sir Keir Starmer and Liberal Democrat leader Sir Ed Davey have all called for a general election.
The SNP leader, who Ms Truss had yet to meet, said there are “no words to describe this utter shambles adequately”.
She added: “It’s beyond hyperbole – & parody.
“Reality though is that ordinary people are paying the price.
“The interests of the Tory party should concern no-one right now.
“A general election is now a democratic imperative.”
The first minister said reports that Boris Johnson may be plotting a return to No 10 were “ludicrous”.
She said in a later interview with LBC the former prime minister had resigned in “deep disgrace” adding “if it wasn’t so serious, it would be laughable”.
Scottish Conservative leader Douglas Ross said Ms Truss has “made a difficult choice” but added it is the “right decision”.
The Moray MP added: “There were no other options after recent events.
“We must now move forward quickly with the election of a new leader and prime minister to restore stability for the good of the country.
“It is vital that the Conservative and Unionist Party unites and continues the hard work of getting the whole of the UK through the big challenges we face.”
Shortest-serving prime minister
Ms Truss has clocked up 44 full days in the role – a long way behind the next shortest premiership, that of Tory statesman George Canning.
He spent 118 full days as PM in 1827 before dying in office from ill health.
Ms Truss was to have overtaken this number of days on January 3, 2023.
But she will fall short by more than two months, with the next prime minister due to be elected within the next week.
Sir Graham Brady said challengers for the Tory leadership will need nominations from at least 100 Conservative MPs to make it to the next stage of the race to replace Liz Truss.
Nominations will begin now and close at 2pm on Monday.